Online system checkpoint alert and handling

Described embodiments provide systems and methods for low disk space notification. Data modules maintain space usage counters for normal stripes and for checkpoint stripes. The data modules also monitor in use space counters; free space counters; and checkpoint space counters. A system wide total space is calculated, as well as in use space, free space and checkpoint space by aggregating worst case space usage from all data modules. A checkpoint free space ratio and an overall system free space ratio are determined and a checkpoint notification is triggered when the checkpoint free space ratio is lower than a first threshold or when the overall system free space ratio is lower than a second threshold. Upon a checkpoint notification being triggered, a checkpoint notification handling routine is executed to free up disk space.